Fix: check if PSK is available

src/compat.h

@@ -54,4 +54,10 @@
 
 //------------------------------------------------------------------------------
 
+#if !defined(LIBRESSL_VERSION_NUMBER) && !defined(OPENSSL_NO_PSK)
+#define LSEC_ENABLE_PSK
+#endif
+
+//------------------------------------------------------------------------------
+
 #endif

src/config.c

@@ -74,6 +74,12 @@ LSEC_API int luaopen_ssl_config(lua_State *L)
   lua_pushboolean(L, 1);
   lua_rawset(L, -3);
 
+#ifdef LSEC_ENABLE_PSK
+  lua_pushstring(L, "psk");
+  lua_pushboolean(L, 1);
+  lua_rawset(L, -3);
+#endif
+
 #ifdef LSEC_ENABLE_DANE
   // DANE
   lua_pushstring(L, "dane");

src/context.c

@@ -707,6 +707,7 @@ static int set_alpn_cb(lua_State *L)
   return 1;
 }
 
+#if defined(LSEC_ENABLE_PSK)
 /**
  * Callback to select the PSK.
  */
@@ -841,6 +842,7 @@ static int set_client_psk_cb(lua_State *L) {
   lua_pushboolean(L, 1);
   return 1;
 }
+#endif
 
 #if defined(LSEC_ENABLE_DANE)
 /*
@@ -893,9 +895,11 @@ static luaL_Reg funcs[] = {
   {"setdhparam",      set_dhparam},
   {"setverify",       set_verify},
   {"setoptions",      set_options},
+#if defined(LSEC_ENABLE_PSK)
   {"setpskhint",      set_psk_identity_hint},
   {"setserverpskcb",  set_server_psk_cb},
   {"setclientpskcb",  set_client_psk_cb},
+#endif
   {"setmode",         set_mode},
 #if !defined(OPENSSL_NO_EC)
   {"setcurve",        set_curve},

src/ssl.lua

@@ -202,7 +202,7 @@ local function newcontext(cfg)
    end
 
    -- PSK
-   if cfg.psk then
+   if config.capabilities.psk and cfg.psk then
       if cfg.mode == "client" then
          if type(cfg.psk) ~= "function" then
             return nil, "invalid PSK configuration"